Arduino accepting only alternate characters - arduino

Question

I am writing an Arduino code to receive SMS from a SIM800 module and then send the same message back to the sender. My code is as follows:
#include<SoftwareSerial.h>
SoftwareSerial mySerial(9, 10);//Connect to pin 9&10 on GSM module
const byte numChars = 128; //character size
char receivedChars[numChars]; // Store data read from SMS
boolean newData = false; //flag to check if new data has arrived
void setup() {
Serial.begin(9600);
mySerial.begin(9600);
Serial.println("<Arduino is ready>");
mySerial.println("AT");
mySerial.println("AT+CMGF=1"); //text mode
mySerial.println("AT+CNMI=1,2,0,0,0");
mySerial.println("AT+CSQ"); //Check signal strength
while (Serial.available())
{
mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
}
while(mySerial.available())
{
Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
}
}
void loop() {
//code for checking sms
scanSMS();
//Print if a new data arrived
showNewData();
delay(25000);
}
void scanSMS() {
static boolean recvInProgress = false;
static byte ndx = 0;
char startMarker = '#'; //Start and end markers. Eg. SMS body will be sent as #status#
char endMarker = '#';
char rc;
while (Serial.available())
{
mySerial.write(Serial.read());//Forward what Serial received to Software Serial Port
}
while (mySerial.available() > 0 && newData == false) {
Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
rc = mySerial.read();
if (recvInProgress == true) {
if (rc != endMarker) {
receivedChars[ndx] = rc;
ndx++;
if (ndx >= numChars) {
ndx = numChars - 1;
}
}
else {
receivedChars[ndx] = '\0'; // terminate the string
recvInProgress = false;
ndx = 0;
newData = true;
}
}
else if (rc == startMarker) {
recvInProgress = true;
}
}
}
/*PRINT IF THERE IS A NEW DATA*/
void showNewData() {
if (newData == true) {
SendMessage(receivedChars);
newData = false;
}
}
/*SEND BACK WHATEVER SMS IS RECEIVED*/
void SendMessage(String receivedChars)
{
Serial.print("here");
mySerial.println("AT+CMGS=\"+xxxxxxxxxx\"\r"); // Replace x with mobile number
mySerial.println("Humidity Alert!");// The SMS text you want to send
mySerial.print(receivedChars);
mySerial.println((char)26);// ASCII code of CTRL+Z
}
The issue is that the module seems to receive only alternate characters instead of the whole message. For example, if I send the text #program#, the Arduino will only print porm or rga. Am I missing something here? Any help is highly appreciated.

Answer 1

You are calling mySerial.read() twice in the while loop.
while (mySerial.available() > 0 && newData == false) {
Serial.write(mySerial.read());//Forward what Software Serial received to Serial Port
rc = mySerial.read();
I think that is why you are not seeing the whole string. read reads the first byte in the buffer and advances.
You want to store a returned value and pass it to the write call like this.
while (mySerial.available() > 0 && newData == false) {
rc = mySerial.read();
Serial.write(rc);//Forward what Software Serial received to Serial Port
....
}